/*
  Copyright (C) 2001-2002 Laurent Martelli <laurent@aopsys.com>
  
  This program is free software; you can redistribute it and/or modify
  it under the terms of the GNU Lesser General Public License as
  published by the Free Software Foundation; either version 2 of the
  License, or (at your option) any later version.

  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU Lesser General Public License for more details.

  You should have received a copy of the GNU Lesser General Public License
  along with this program; if not, write to the Free Software
  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */

package org.objectweb.jac.aspects.authentication;

/**
 * The role of a class that implements this interface is to ensure
 * that the <code>AuthenticationAC.USER</code> contextual attribute
 * corresponds to an authenticated user (an existing user). */

public interface Authenticator {   
    /**
     * Authenticates the current user.
     * @return the username of the user.
     */
    String authenticate() throws AuthenticationFailedException;
}
